swap_pager.c:

Fixed long standing bug in freeing swap space during object collapses.
Fixed 'out of space' messages from printing out too often.
Modified to use new kmem_malloc() calling convention.
Implemented an additional stat in the swap pager struct to count the
amount of space allocated to that pager. This may be removed at some
point in the future.
Minimized unnecessary wakeups.

vm_fault.c:
Don't try to collect fault stats on 'swapped' processes - there aren't
any upages to store the stats in.
Changed read-ahead policy (again!).

vm_glue.c:
Be sure to gain a reference to the process's map before swapping.
Be sure to lose it when done.

kern_malloc.c:
Added the ability to specify if allocations are at interrupt time or
are 'safe'; this affects what types of pages can be allocated.

vm_map.c:
Fixed a variety of map lock problems; there's still a lurking bug that
will eventually bite.

vm_object.c:
Explicitly initialize the object fields rather than bzeroing the struct.
Eliminated the 'rcollapse' code and folded it's functionality into the
"real" collapse routine.
Moved an object_unlock() so that the backing_object is protected in
the qcollapse routine.
Make sure nobody fools with the backing_object when we're destroying it.
Added some diagnostic code which can be called from the debugger that
looks through all the internal objects and makes certain that they
all belong to someone.

vm_page.c:
Fixed a rather serious logic bug that would result in random system
crashes. Changed pagedaemon wakeup policy (again!).

vm_pageout.c:
Removed unnecessary page rotations on the inactive queue.
Changed the number of pages to explicitly free to just free_reserved
level.

Submitted by:	John Dyson

1 files changed, 23 insertions, 6 deletions

diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index 5ba589570c07..941b0dcddf55 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -61,7 +61,7 @@
  * any improvements or extensions that they make and grant Carnegie the
  * rights to redistribute these changes.
  *
- * $Id: vm_map.c,v 1.11 1995/01/10 07:32:46 davidg Exp $
+ * $Id: vm_map.c,v 1.12 1995/01/24 10:13:02 davidg Exp $
  */
 
 /*
@@ -216,6 +216,9 @@ vmspace_free(vm)
 	register struct vmspace *vm;
 {
 
+	if (vm->vm_refcnt == 0)
+		panic("vmspace_free: attempt to free already freed vmspace");
+
 	if (--vm->vm_refcnt == 0) {
 		/*
 		 * Lock the map, to wait out all other references to it.
@@ -225,6 +228,10 @@ vmspace_free(vm)
 		vm_map_lock(&vm->vm_map);
 		(void) vm_map_delete(&vm->vm_map, vm->vm_map.min_offset,
 		    vm->vm_map.max_offset);
+		vm_map_unlock(&vm->vm_map);
+		while( vm->vm_map.ref_count != 1)
+			tsleep(&vm->vm_map.ref_count, PVM, "vmsfre", 0);
+		--vm->vm_map.ref_count;
 		pmap_release(&vm->vm_pmap);
 		FREE(vm, M_VMMAP);
 	}
@@ -448,10 +455,15 @@ vm_map_deallocate(map)
 		return;
 
 	simple_lock(&map->ref_lock);
-	c = --map->ref_count;
+	c = map->ref_count;
 	simple_unlock(&map->ref_lock);
 
-	if (c > 0) {
+	if (c == 0)
+		panic("vm_map_deallocate: deallocating already freed map");
+
+	if (c != 1) {
+		--map->ref_count;
+		wakeup((caddr_t) &map->ref_count);
 		return;
 	}
 	/*
@@ -459,11 +471,14 @@ vm_map_deallocate(map)
 	 */
 
 	vm_map_lock(map);
-
 	(void) vm_map_delete(map, map->min_offset, map->max_offset);
+	--map->ref_count;
+	if( map->ref_count != 0) {
+		vm_map_unlock(map);
+		return;
+	}
 
 	pmap_destroy(map->pmap);
-
 	FREE(map, M_VMMAP);
 }
 
@@ -1039,8 +1054,10 @@ vm_map_protect(map, start, end, new_prot, set_max)
 
 	current = entry;
 	while ((current != &map->header) && (current->start < end)) {
-		if (current->is_sub_map)
+		if (current->is_sub_map) {
+			vm_map_unlock(map);
 			return (KERN_INVALID_ARGUMENT);
+		}
 		if ((new_prot & current->max_protection) != new_prot) {
 			vm_map_unlock(map);
 			return (KERN_PROTECTION_FAILURE);